Simplified Assessment of the Effects of Columns Shortening on the Response of Tall Concrete Buildings

The constructive process as well as the time-dependent effects must be considered in the assessment of the response of complex concrete structures. For tall buildings, the adequate prediction of vertical elements shortening is required to determine its effects on other structural and nonstructural elements, usually overestimated by linear elastic analysis. Thus, simple numerical methods which make it possible to consider the most relevant aspects of the structural behaviour may be useful in the early stages of a project. In the research presented herein a simplified method, which considers the viscoelasticity of concrete as well as the construction sequence, was used. Its adequacy was assessed by comparison of the results for a tall concrete building with those obtained with a commercial software which incorporates a nonlinear staged construction analysis package. The good correlation between the obtained results indicates that the simplified method used may be applied to help make appropriate design choices.